U.S. patent number 9,379,031 [Application Number 14/548,504] was granted by the patent office on 2016-06-28 for display panel for display device.
This patent grant is currently assigned to LG Display Co., Ltd.. The grantee listed for this patent is LG Display Co., Ltd.. Invention is credited to SangBin Lee.
United States Patent |
9,379,031 |
Lee |
June 28, 2016 |
Display panel for display device
Abstract
Disclosed is a display panel in which a jumping wiring made of a
heterogeneous material for the prevention of static electricity
connects a signal pad with a test wiring of an array substrate, or
a display panel, and induces a discharge of the static electricity
when the static electricity generated in an array test process
flows into the display panel, thereby preventing damage to the
display panel.
Inventors: |
Lee; SangBin (Gyeongsangbuk-do,
KR) |
Applicant: |
Name |
City |
State |
Country |
Type |
LG Display Co., Ltd. |
Seoul |
N/A |
KR |
|
|
Assignee: |
LG Display Co., Ltd. (Seoul,
KR)
|
Family
ID: |
51485483 |
Appl.
No.: |
14/548,504 |
Filed: |
November 20, 2014 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20150144915 A1 |
May 28, 2015 |
|
Foreign Application Priority Data
|
|
|
|
|
Nov 28, 2013 [KR] |
|
|
10-2013-0145880 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L
22/32 (20130101); G02F 1/136204 (20130101); G02F
1/1309 (20130101); G02F 1/1345 (20130101); H01L
27/3276 (20130101); G09G 3/006 (20130101); G02F
1/136254 (20210101); G02F 1/13629 (20210101) |
Current International
Class: |
H01L
27/32 (20060101); G02F 1/1362 (20060101); G02F
1/1345 (20060101); G02F 1/13 (20060101); H01L
21/66 (20060101); G09G 3/00 (20060101); H01L
21/00 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Seven; Evren
Attorney, Agent or Firm: Morgan, Lewis & Bockius LLP
Claims
What is claimed is:
1. A display panel, comprising: a plurality of gate lines and data
lines; an active area having a plurality of pixels, each of which
is defined at an intersection area between a respective gate line
and data line; a plurality of signal pads arranged in a non-active
area, each signal pad configured so as to apply a gate signal or a
data signal to a respective gate line or data line; a test wiring
portion arranged opposite to the active area relative to a cutting
line of the display panel, the test wiring portion electrically
connected to the plurality of signal pads in order to be used in a
test of the display panel; a plurality of jumping wirings, each
jumping wiring being interposed between a respective signal pad and
the test wiring portion and electrically connecting the signal pad
with the test wiring portion, the jumping wirings being formed of a
material different from that of the signal pads and the test wiring
portion, and the jumping wirings being on a layer different from
that of the signal pads and the test wiring portion, wherein the
signal pads and the test wiring portion are formed of a gate metal
material or a source/drain metal material, and the jumping wirings
are formed of a material of a pixel electrode.
2. The display panel of claim 1, wherein each of the signal pads is
configured as a gate pad so as to apply a gate signal to a
respective gate line.
3. The display panel of claim 1, wherein each jumping wiring is
configured such that a connection of the jumping wiring with one of
the signal pad and the test wiring portion breaks down due to a
heterogeneous material therebetween when static electricity
generated in a process of testing the display panel flows into the
display panel, so as to prevent damage of the display panel.
4. The display panel of claim 1, wherein the signal pads and the
test wiring portion are formed of at least one of aluminum,
aluminum alloy, copper, copper alloy, molybdenum, and molybdenum
alloy, and the jumping wirings are formed of a metal oxide which is
one of Indium-Tin-Oxide and Indium-Zinc-Oxide, or a combination of
a metal and an oxide which is one of ZnO:Al and SnO2:Sb.
5. A display panel, comprising: a plurality of gate lines and data
lines; an active area having a plurality of pixels, each of which
is defined at an intersection area between a respective gate line
and data line; a plurality of signal pads arranged in a non-active
area, each signal pad configured so as to apply a gate signal or a
data signal to a respective gate line or data line; a test wiring
portion arranged opposite to the active area relative to a cutting
line of the display panel, the test wiring portion electrically
connected to the plurality of signal pads in order to be used in a
test of the display panel; a plurality of jumping wirings, each
jumping wiring being interposed between a respective signal pad and
the test wiring portion and electrically connecting the signal pad
with the test wiring portion, the jumping wirings being formed of a
material different from that of the signal pads and the test wiring
portion, and the jumping wirings being on a layer different from
that of the signal pads and the test wiring portion, wherein the
display panel is an OLED display panel including an organic light
emitting device, the signal pads and the test wiring portion are
formed of a gate metal material or a source/drain metal material,
and the jumping wirings are formed of a material identical to that
of a first electrode or a second electrode, which are arranged on
opposite sides of an organic light emitting layer, and the jumping
wirings are on a layer identical to that of the first electrode or
the second electrode, wherein the first electrode is an anode and
the second electrode is a cathode.
6. The display panel of claim 1, wherein the jumping wiring has a
length longer than 500 .mu.m.
7. A display panel, comprising: a plurality of gate lines and data
lines; an active area having a plurality of pixels, each of which
is defined at an intersection area between a respective gate line
and data line; a plurality of signal pads arranged in a non-active
area, each signal pad configured so as to apply a gate signal or a
data signal to a respective gate line or data line; a test wiring
portion arranged opposite to the active area relative to a cutting
line of the display panel, the test wiring portion electrically
connected to the plurality of signal pads in order to be used in a
test of the display panel; a plurality of jumping wirings, each
jumping wiring being interposed between a respective signal pad and
the test wiring portion and electrically connecting the signal pad
with the test wiring portion; and a plurality of connection
wirings, each connection wiring being interposed between a
respective signal pad and the test wiring portion and formed of a
material identical to that of the signal pad and the test wiring
portion, wherein in each case the jumping wiring forms a connection
at least one of between the signal pad and the connection wiring
and between the test wiring portion and the connection wiring.
8. The display panel of claim 7, wherein the signal pads, the test
wiring portion, and the connection wiring are formed of a gate
metal material or a source/drain metal material, and the jumping
wirings are formed of a material of a pixel electrode.
9. The display panel of claim 8, wherein the signal pads, the test
wiring portion, and the connection wirings are formed of at least
one of aluminum, aluminum alloy, copper, copper alloy, molybdenum,
and molybdenum alloy, and the jumping wirings are formed of a metal
oxide which is one of Indium-Tin-Oxide (ITO) and Indium-Zinc-Oxide
(IZO), or a combination of a metal and an metal oxide which is one
of ZnO:Al and SnO2:Sb.
10. The display panel of claim 7, wherein the display panel is an
OLED display panel including an organic light emitting device, the
signal pads, the test wiring portion, and the connection wirings
are formed of a gate metal material or a source/drain metal
material, and the jumping wiring is formed of a material identical
to that of a first electrode or a second electrode, which are
arranged on opposite sides of an organic light emitting layer, and
the jumping wiring is on a layer identical to that of the first
electrode or the second electrode, wherein the first electrode is
an anode and the second electrode is a cathode.
11. The display panel of claim 1, wherein the signal pads and the
test wiring portion are formed of the same material and are on the
same layer.
12. The display panel of claim 1, wherein the signal pads are
formed of a different material and are on a different layer than
the test wiring portion.
Description
CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority from Korean Patent Application No.
10-2013-0145880, filed on Nov. 28, 2013, which is hereby
incorporated by reference for all purposes as if fully set forth
herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a display panel for a display
device, and more particularly, to a display panel and a method of
fabricating the same, which is capable of preventing the damage of
a substrate due to static electricity generated on the panel in an
array test process.
2. Description of the Prior Art
With the development of information society, various types of
requirements for a display device for displaying an image are
increasing and, recently, various display devices, such as a Liquid
Crystal Display (LCD), a Plasma Display Panel (PDP), and an Organic
Light Emitting Diode Display Device (OLED), are being used.
The liquid crystal display among the display devices includes an
array substrate including a thin film transistor, an upper
substrate having a color filter and/or a black matrix, and a liquid
crystal layer interposed between the array substrate and the upper
substrate. The liquid crystal display is a device in which an
arranged status of the liquid crystal is controlled depending on an
electric field applied between two electrodes of a pixel area,
thereby adjusting permeability of light to display an image.
Further, the OLED display device includes a thin film transistor,
such as a switching transistor and a driving transistor, first and
second electrodes, a first substrate including an organic light
emitting layer arranged between the first and second electrodes,
and a second substrate adhered onto the first substrate. The OLED
display device is a device in which the extent of light emitting of
the organic material is controlled depending on a magnitude of a
voltage or an electric current applied between two electrodes of a
pixel area.
FIG. 1 shows an example of a display panel or an array substrate of
a related art display device.
A display panel 100 for the liquid crystal display device or the
OLED display device has an active area AA for providing an image to
a user, and a non-active area NA, which is a peripheral area of the
active area AA. The display panel is fabricated by adhering the
first substrate, which is the array substrate in which the thin
film transistor and the like are formed to define a pixel area, to
the second substrate which is an upper substrate in which a black
matrix and/or a color filter layer are formed.
In the case of the OLED display panel, the second substrate may
only function as a protection substrate.
The array substrate or the first substrate on which the thin film
transistor is formed includes a plurality of gate lines GL
extending in a first direction, and a plurality of data lines DL
extending in a second direction perpendicular to the first
direction. Each gate line and each data line define one pixel area
P. One or more thin film transistors are formed in one pixel area
P, and a gate electrode and a source electrode of each thin film
transistor may be connected to a gate line and a data line,
respectively.
Further, a gate pad 110 is formed at an end of each gate line GL as
a signal pad for applying a gate signal. In FIG. 1, a gate pad (not
shown) may be additionally formed at a right side in addition to a
gate pad 110 formed at a left side.
Further, a data pad 120 is formed at an upper portion or a lower
portion of the display panel 100 as a signal pad for applying a
data signal to an end of each data line DL.
On the other hand, an array test process is performed to test
whether a defect (for example, a point defect such as a fault of a
transistor or a line defect such as a short) in an electrical
property of the panel is present after a process of fabricating the
array substrate is complete. For the array test, test wirings
extend longitudinally in both directions of a display panel in
order to simultaneously apply a test signal to all gate pads and/or
data pads.
That is, as shown in FIG. 1, a test wiring 140 for data lines
simultaneously connecting a plurality of data pads 120
longitudinally extends in the first direction substantially
parallel to the gate lines, and a test wiring 130 for gate lines
simultaneously connecting a plurality of gate pads 110
longitudinally extends in the second direction substantially
parallel to the data lines.
Further, the test wirings 130 and 140 and each pad are connected by
connection wirings 150 and 160, which are formed of a metal
material identical to that of the pads on an identical layer as
that of the pads or on different layers than that of the pads.
When an array test is complete through the test wiring after
fabricating the array substrate or the display panel, the display
panel is cut along a cutting line 170, thereby completing a process
of fabricating the individual display panel.
On the other hand, static electricity may be generated in the
process of the array test, and at this time a large voltage or
electric current may be momentarily applied. Since the
above-mentioned test wirings 150 and 160 are formed longitudinally
as a single metal wire, they have a large amount of electric
charge. Accordingly, electric charges caused by the static
electricity flow into the panel through the test wiring and the
connection wiring so as to cause breakdown of internal wirings of
the thin film transistor or the panel, thereby causing a defect of
the panel.
That is, since the related art test wiring and connection wiring
for the array test are formed of a metal pattern identical to the
data pad or the gate pad, and have the large amount of electric
charge, there is a problem in that static electricity generated in
the array test process flows into the panel, thereby causing damage
of the panel.
SUMMARY OF THE INVENTION
Accordingly, the present invention is directed to a display panel
that substantially obviates one or more of the problems due to
limitations and disadvantages of the related art.
An object of the present invention is to provide a display panel
which is capable of preventing damage thereof due to static
electricity generated in an array test.
Another object of the present invention is to provide a display
panel which is capable of preventing an inflow of static
electricity into the display panel or an array substrate in a
process of testing the array substrate.
Still another object of the present invention is to provide a
display panel in which a jumping wiring made of a heterogeneous
material for a prevention of static electricity is connected
between a signal pad and a test wiring of an array substrate or a
display panel, and induces a discharge of the static electricity
when the static electricity generated in a process of testing a
substrate flows into the display panel, thereby preventing damage
of the display panel which is caused by the static electricity
which is generated in the test process and flows into the display
panel.
Yet another object of the present invention is to prevent defects
of a display panel due to the static electricity generated in the
array test process of the display panel for the liquid crystal
display device or the organic light emitting display device.
A further object of the present invention is to provide a
connection of a jumping wiring that induces a breakdown of static
electricity when static electricity generated in the substrate test
process flows into the display panel, thereby preventing the damage
or defect of the inside of the panel.
Additional features and advantages of the invention will be set
forth in the description which follows, and in part will be
apparent from the description, or may be learned by practice of the
invention. The objectives and other advantages of the invention
will be realized and attained by the structure particularly pointed
out in the written description and claims hereof as well as the
appended drawings.
To achieve these and other advantages and in accordance with the
purpose of the present invention, as embodied and broadly
described, a display panel comprises a plurality of gate lines and
data lines; an active area having a plurality of pixels, each of
which is defined at an intersection area between a respective gate
line and data line, a plurality of signal pads arranged in a
non-active area, each signal pad configured so as to apply a gate
signal or a data signal to a respective gate line or data line, and
a test wiring portion arranged out of a cutting line of the display
panel and electrically connected to the plurality of signal pads in
order to be used in a test of the display panel; a plurality of
jumping wirings, each jumping wiring being interposed between a
respective signal pad and the test wiring portion and electrically
connecting the signal pad with the test wiring portion, the jumping
wirings being formed of a material different from that of the
signal pads and the test wiring portion on a layer different from
that of the signal pads and the test wiring portion.
It is to be understood that both the foregoing general description
and the following detailed description are exemplary and
explanatory and are intended to provide further explanation of the
invention as claimed.
BRIEF DESCRIPTION OF DRAWINGS
The accompanying drawings, which are included to provide a further
understanding of the invention and are incorporated in and
constitute a part of this specification, illustrate embodiments of
the invention and together with the description serve to explain
the principles of the invention. In the drawings:
FIG. 1 is a view schematically illustrating a plane of an array
substrate or a display panel for a related art display device;
FIGS. 2, 3 and 4 are views illustrating a configuration of a first
embodiment, in which FIG. 2 is a plan view illustrating a test
wiring portion on an array substrate according to the first
embodiment, FIG. 3 is a sectional view illustrating the test wiring
portion on the array substrate, and FIG. 4 is a view illustrating a
fabricating process;
FIGS. 5, 6 and 7 are views illustrating a configuration of a second
embodiment, in which FIG. 5 is a plan view illustrating a test
wiring portion on an array substrate according to the second
embodiment, FIG. 6 is a sectional view illustrating the test wiring
portion, and FIG. 7 is a view illustrating a fabricating process;
and
FIGS. 8A and 8B are views illustrating modifications of the first
and second embodiments.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
Hereinafter, exemplary embodiments will be described with reference
to the accompanying drawings. In the following description, the
same elements will be designated by the same reference numerals
although they are shown in different drawings. Further, in the
following description of the present invention, a detailed
description of known functions and configurations incorporated
herein will be omitted when it may not be required for the
understanding of the subject matter of this invention.
In addition, terms, such as first, second, A, B, (a), (b) or the
like may be used herein when describing components of this
invention. Each of these terminologies is not used to define an
essence, order or sequence of a corresponding component but used
merely to distinguish the corresponding component from other
component(s). It should be noted that if it is described in the
specification that one component is "connected," "coupled" or
"joined" to another component, a third component may be
"interposed" between the first and second components, although the
first component may be directly "connected", "coupled" or "joined"
to the second component.
This invention is to solve the problems in which the static
electricity generated in an array test process flows into the panel
through the test wiring, connection wiring and signal pad and
damages the elements in the display panel. For this purpose, in
this invention, a jumping wiring formed of a material different
from the test wiring and the signal pads is formed between the
signal pad and the test wiring, which breaks down due to the
heterogeneous material (in other words, different material) when
static electricity generated in the array test process flows into
the display panel, thereby preventing damages of the display panel
due to static electricity.
For the purpose, two embodiments of the present invention will be
described below as an example, but the present invention is not
limited to these embodiments.
The first embodiment includes a jumping wiring formed of a material
different from that of a signal pad and a test wiring portion on a
layer different from that of the signal pad and the test wiring
portion, which is interposed between a test wiring portion and a
signal pad such as a gate pad or a data pad to electrically connect
the signal pad to the test wiring portion.
Further, the second embodiment includes an additional connection
wiring arranged between the signal pad portion and the test wiring
portion, and a jumping wiring interposed between the signal pad
portion and the connection wiring portion and/or between the test
wiring portion and the connection wiring portion, in which the
jumping wiring is formed of a material different from that of the
signal pad portion, the test wiring portion, and the connection
wiring portion on a layer different from that of the signal pad
portion, the test wiring portion, and the connection wiring
portion.
Hereinafter, in each description, "signal pad portion" refers to
all kinds of metal patterns, which are electrically connected to a
gate pad and a data pad and used to apply a gate signal and a data
signal to a gate line and/or a data line of a display panel, as
well as a gate pad disposed in a non-active area and the data
pad.
Further, "test wiring portion" is a metal pattern which is arranged
outside of a cutting line of the display panel and electrically
connects a plurality of signal pads, and includes all kinds of
wirings used to apply an inspection signal to an inside of the
panel in order to perform various inspections after the fabrication
of the display panel. The "test wiring" may be expressed by another
term such as a test line, a shorting-bar, an auto probe test line,
and the like.
Hereinafter, a configuration of the two embodiments will be
described in detail with reference to the drawings.
FIGS. 2, 3 and 4 are views illustrating a configuration of the
first embodiment of the present invention, in which FIG. 2 is a
plan view illustrating a test wiring portion on an array substrate
according to the first embodiment of the present invention, FIG. 3
is a sectional view illustrating the test wiring portion on the
array substrate, and FIG. 4 is a view illustrating a fabricating
process.
As shown in FIG. 2, according to the first embodiment, the display
panel, which includes (for example, similarly as illustrated in
FIG. 1) an active area having a plurality of pixels, each of which
is defined at an intersection area between a gate line and a data
line, a signal pad 210 disposed in the non-active area, for
applying a gate signal or a data signal to the gate line or the
data line, and test wiring portions 220 and 220' disposed outside
of a cutting line 170 and electrically connected to the signal pad
in order to use in a test of a substrate, includes a jumping wiring
230 interposed between the signal pad 210 and the test wiring
portions 220 and 220' and electrically connected to the signal pad
and the test wiring portions. The jumping wiring 230 is formed of a
material different from the signal pad and the test wiring portions
on a layer different from that of the signal pad and the test
wiring portions so as to prevent static electricity.
As shown in FIG. 2, it will be described that the test wiring
portion includes a test wiring 220 as a primary wiring extending in
a longitudinal or transverse direction of the panel and an
inspection pad 220' extending from the primary wiring and connected
to each signal pad. However, the test wiring portion is not limited
thereto, and it is described below that the test wiring portion
includes the test wiring 220 and the inspection pad 220' for
convenience.
That is, in the first embodiment as shown in FIG. 2, the test
wiring portions 220 and 220' and the signal pad 210 are configured
of an identical material on the same layer, and the jumping wiring
230 to electrically connect the inspection pad 220' and the signal
pad 210, which are exposed through a respective contact hole 240,
may be formed of a material different from the test wiring portion
and the signal pad on a layer different from the test wiring
portion and the signal pad.
Especially, in the case where the signal pad and the test wiring
portion are prepared for the inspection of a gate signal pad and a
gate line, the signal pad 210 and the test wiring portions 220 and
220' are formed of a gate metal layer, and the jumping wiring 230
may be configured of a transparent electrode material identical to
that of a pixel electrode and different from that of the gate metal
layer.
Further, in the case where the signal pad and the test wiring
portion are prepared for the inspection of a data signal pad and a
data line, the signal pad 210 and the test wiring portions 220 and
220' are formed of a source/drain metal layer, and the jumping
wiring 230 may be configured of the transparent electrode material
identical to that of the pixel electrode and different from that of
the source/drain metal layer.
The material of the gate metal layer or the source/drain metal
layer which is identical to that of the signal pad and the test
wiring portion may include one or more metal material having a low
resistance property such as aluminum (Al), aluminum alloy such as
aluminum neodym alloy (AlNd), copper (Cu), copper alloy, molybdenum
(Mo), and molybdenum alloy such as molybdenum titanium alloy
(MoTi).
Further, in the embodiment, the pixel electrode, which may be
formed of a material of the jumping wiring, may be a transparent
electrode. That is, the pixel electrode and the jumping wiring may
be formed of a transparent conductive material having a relatively
large work function value, for example, a metal oxide such as
Indium Tin Oxide (ITO) or Indium Zinc Oxide (IZO), or a combination
of a metal and an oxide such as ZnO:Al or SnO2:Sb.
As shown in FIGS. 2 and 3, on the other hand, the signal pad 210
and the inspection pad 220' may be formed to be a gate metal
pattern, and a respective contact hole 240 is formed to penetrate a
gate insulation layer 314 and a protection layer (passivation layer
322) which are sequentially formed on the signal pad 210 and the
inspection pad 220', so as to expose a part of the signal pad 210
and the inspection pad 220'. Further, the jumping wiring 230 formed
of a material of the pixel electrode may electrically connect the
signal pad 210 with the inspection pad 220' through the contact
hole.
On the other hand, the jumping wiring 230 may have a length equal
to or longer than 500 .mu.m.
FIG. 3 is a sectional view illustrating the test wiring portion
according to the first embodiment of the present invention, taken
along a line I-I' of FIG. 2, and shows a sectional view
illustrating the test wiring portion along with a thin film
transistor on a right side in order to help understanding.
As shown in a sectional view of FIG. 3 taken along the line I-I' on
a left side of FIG. 3, the display panel or an array substrate
according to the first embodiment includes the test wiring portions
220 and 220' and the signal pad 210 formed of a material identical
to that of a gate electrode 312 of the thin film transistor in the
same process as that of forming the gate electrode 312, and a
respective contact hole 240 formed to expose an end of the
inspection pad 220' and the signal pad 210 through a part of a gate
insulation layer 314 and a protection layer 322 which are
sequentially formed on the test wiring portions 220 and 220' and
the signal pad 210. The display panel or the array substrate
further includes a jumping wiring 230 which is formed of a material
identical to that of a pixel electrode 326 in the thin film
transistor area in the same process as that of forming the pixel
electrode 326 and electrically connects the inspection pad 220'
with the signal pad 210 through the contact holes 240.
According to the first embodiment, in the case where static
electricity is generated in a process of inspecting the panel, such
as an array test and the like, when an electric charge of static
electricity reaches the jumping wiring 230 configured of a
heterogeneous material (in other words, a material that is
different from a material of the test wiring portions 220 and 220'
and/or of the signal pad 210) while it is electrified through the
test wiring portions 220 and 220', a movement of the electric
charge is disturbed due to a difference of electric conductivity,
and a connection of two materials is broken due to a difference of
mobility of the electric charge so as to cause a phenomenon in
which two materials are electrically short-circuited. Accordingly,
it is possible to prevent an inflow of the static electricity into
the panel through the test wiring portions.
Each layer in the thin film transistor area shown on a right side
of FIG. 3 is merely shown in order to help the understanding of a
process or a material of forming the signal wiring, according to
the present invention.
A configuration (material, process, and the like) of each layer of
the thin film transistor will be described in detail with reference
to FIG. 4 illustrating a process of fabricating the display
panel.
FIG. 4 is a sectional view illustrating a process of fabricating
the display panel (array substrate) having a configuration of
preventing static electricity according to the first embodiment of
the present invention.
Firstly, a gate metal material composed of at least one or more
metal material such as aluminum (Al), aluminum alloy such as
aluminum neodym alloy (AlNd), copper (Cu), copper alloy, molybdenum
(Mo), and molybdenum alloy such as molybdenum titanium alloy
(MoTi), is deposited on a surface of a substrate such as a
transparent insulation substrate 310 consisting of glass or plastic
material to form a first metal layer. Next, the first metal layer
is patterned by performing a masking process or a photolithography
process including a series of processes of coating a photoresist,
exposing the photoresist by using a photo-mask, developing the
exposed photoresist, etching a part of the first metal layer, and
stripping the photoresist, so as to form the test wiring portion
220, which has a single layer or multilayer configuration and
extends in a longitudinal direction of the panel (in a direction
parallel with the data line), the test wiring portion (inspection
pad) 220', and the signal pad (e.g. gate pad) 210.
In the processes, the gate line (not shown) connected to each pixel
area and a gate electrode 312 of a driving TFT or a pixel TFT may
be simultaneously formed together (see step A of FIG. 4).
Next, after a mask having a transparent area is arranged in a
necessary area, a first inorganic insulation substance, for
example, any one of silicon oxide (SiO2) or silicon nitride (SiNx),
is deposited to form a gate insulation layer 314 formed of the
inorganic insulation substance.
The gate insulation layer 314 having a single layer is shown in
FIG. 4, but it may have at least two layers consisting of different
materials respectively.
Next, any one of Zinc Oxide based Oxide, e.g., Indium Gallium Zinc
Oxide (IGZO), Zinc Tin Oxide (ZTO), and Zinc Indium Oxide (ZIO) is
deposited or coated as an oxide semiconductor material on the gate
insulation layer 314 to form an oxide semiconductor layer, and the
oxide semiconductor layer (not shown) is patterned by performing a
mask process to form an active layer or a semiconductor layer 316
in the form of an island on a gate electrode 312 of each thin film
transistor (TFT).
The semiconductor layer 316 may also be formed of a poly-silicon,
but it is not limited thereto. The semiconductor layer 316 may be
formed of the oxide semiconductor or one of pure amorphous silicon
and impure amorphous silicon.
In the case that the semiconductor layer 316 is formed of the poly
silicon, after an amorphous silicon layer is formed on the
substrate 310, the amorphous silicon layer is crystalized to form a
poly crystal silicon layer, and then the poly crystal silicon layer
is patterned to form the semiconductor layer 316. The amorphous
silicon may be formed by using a chemical vapor deposition, or a
physical vapor deposition. Further, when the amorphous silicon is
formed, or after the amorphous silicon is formed, a dehydrogenation
treatment of the amorphous silicon may be performed to lower a
concentration of hydrogen. Further, the crystallization of the
amorphous silicon layer may be performed by using any one of a
rapid thermal annealing (RTA) process, a solid-phase
crystallization (SPC) process, a metal induced crystallization
(MIC) process, a metal induced lateral crystallization (MILC)
process, a super grain silicon (SGS) process, an excimer laser
crystallization (ELA) process, or a sequential lateral
solidification (SLS) process.
Then, an ohmic contact layer 318 is formed on the semiconductor
layer 316 in order to reduce a contact resistance, and a
source/drain electrode 320 is formed on the ohmic contact layer
318. Particularly, after the semiconductor layer 316 and/or the
ohmic contact layer 318 are formed, a source/drain metal layer
consisting of a material, such as copper (Cu), chrome (Cr),
molybdenum (Mo), titanium (Ti), tantalum (Ta), molybdenum alloy (Mo
alloy), and the like, is deposited on a surface to form a second
metal layer, and then the second metal layer is patterned by
performing a mask process or a photolithographic process to form a
source/drain electrode 320.
In the process, a data line (not shown) connected to each pixel
area may be simultaneously formed together with the source/drain
electrode 320.
An etch stopper, which has an island shape and consists of an
inorganic insulation material, may be formed instead of, or in
addition to, the ohmic contact layer 318, and then the source/drain
metal layer may be patterned on the etch stopper, thereby forming a
source electrode and a drain electrode contacting an upper surface
of both ends of the semiconductor layer 316.
Further, during the patterning of the source/drain metal layer, a
photoresist film having three thicknesses is formed as a single
mask by using a half-tone mask process having a semi-transparent
property at some areas so that the patterning of two layers may be
performed by a single masking process.
Next, after the source/drain metal pattern is formed, a protection
layer 322 or a passivation layer is formed on the source/drain
metal pattern (see step B of FIG. 4).
Then, a contact hole 324 is formed to penetrate the protection
layer 322 and to expose a part of the drain electrode in the thin
film transistor area in order to connect the pixel electrode and
the drain electrode. In this process, the masking process or the
photolithographic process is performed to pattern the protection
layer 322 or the passivation layer, and some area of the gate
insulation layer 314 and the protection layer 322 is etched so as
to form contact holes 240, which expose a part of an end of the
inspection pad 220' and the signal pad 210 (see step C of FIG. 4),
respectively.
In the process of forming the pixel electrode, the jumping wiring
230 is formed to connect the inspection pad 220' and the signal pad
210 through the contact holes 240, which may be formed of a
material identical to that of the pixel electrode (see step D of
FIG. 4). That is, the jumping wire 230 may be formed of a
transparent conductive material having a relatively large work
function value such as a metal oxide such as Indium-Tin-Oxide (ITO)
and Indium-Zinc-Oxide (IZO), a combination of an oxide and a metal,
such as ZnO:Al or SnO2:Sb, but it is not limited thereto.
Further, the embodiments of the present invention are not limited
to a configuration of the thin film transistor shown in FIGS. 2 to
4. If the embodiments of the present invention include a
configuration in which the test wiring portion and the signal pad
are electrically connected by means of the jumping wiring formed of
a material different from that of the test wiring and the signal
pad on a layer different from that of the test wiring, they may be
applied to a configuration of other types of the thin film
transistor or a display panel having a different shape.
That is, in the case of the OLED display device, the signal pad 210
and the test wiring portions 220 and 220' may be formed of a gate
metal material (layer) or a source/drain metal material (layer),
and the jumping wiring 230 may be formed of a material identical to
that of a first electrode (anode or cathode) or a second electrode
(cathode or anode), which are disposed on both ends of an organic
light emitting layer. In addition, the jumping wiring 230 may be
formed on a layer identical to that of the first electrode or the
second electrode. Particularly, the jumping wiring 230 may be
formed of a material identical to the first electrode or the second
electrode consisting of a transparent conductive material, e.g.,
Indium-Tin-Oxide (ITO) or Indium-Zinc-Oxide (IZO), on a layer
identical to that of the first electrode or the second electrode,
according to a type, e.g., n type or p type, of a driving
transistor (DTr) of the OLED substrate.
Further, although it is shown in FIGS. 2 to 4 that both the test
wiring portions 220 and 220' and the signal pad 210 are formed of
the gate metal layer, in the case the signal pad and the test
wiring are for the data lines, the test wiring portions 220 and
220' and the signal pad 210 may be formed of a material identical
to that of the source/drain metal layer shown in FIGS. 2 to 4 in a
process identical to that of forming the source/drain metal
layer.
In the first embodiment, although it is not shown, the auto probe
test wiring portions 220 and 220' and the signal pad 210 may be
simultaneously formed along with the source/drain metal layer, and
the contact holes 240 may be formed to penetrate the protection
layer 322 on the source/drain metal layer. Further, the jumping
wiring 230 may be formed of a material identical to that of the
pixel electrode in a process identical to that of forming the pixel
electrode.
FIGS. 5, 6 and 7 are views illustrating a configuration of the
second embodiment of the present invention, in which FIG. 5 is a
plan view illustrating a test wiring portion on an array substrate
according to the second embodiment of the present invention, FIG. 6
is a sectional view illustrating the test wiring portion, and 7 is
a view illustrating a fabricating process.
According to the second embodiment shown in FIGS. 5, 6 and 7, the
display panel includes (for example, similarly as illustrated in
FIG. 1) an active area having a plurality of pixels each of which
is defined at an intersection area between a gate line and a data
line, a signal pad 510 arranged in a non-active area for applying a
gate signal or a data signal to the gate line or the data line, and
test wiring portions 520 and 520' which are arranged outside of the
cutting line 170 and electrically connected to the signal pad in
order to use in a test of the display panel. The display panel may
include a connection wiring 550 interposed between the signal pad
510 and the test wiring portions 520 and 520', and formed of a
material identical to that of the signal pad and the test wiring
portions, and jumping wirings 530 and 530' which establish an
electric connection between the connection wiring 550 and the test
wiring portions 520, 520', and an electric connection between the
connection wiring 550 and the signal pad 510, respectively, and
which are formed of a material different from that of the signal
pad and the test wiring portions on a layer different from that of
the signal pad and the test wiring portions.
In the embodiment shown in FIGS. 5 to 7, the signal pad 510 and the
test wiring portions 520 and 520' are formed of a gate metal layer,
the connection wiring 550 is formed of a source/drain metal, and
the jumping wirings 530 and 530' are formed of a material of a
pixel electrode. The jumping wirings 530 and 530' may be
electrically connected to the test wiring portions 520 and 520' and
the signal pad 510, respectively, through first contact holes 570
and 590 formed to penetrate a gate insulation layer 614 and a
protection layer 622 so as to expose a part of the test wiring
portions 520 and 520' or the signal pad 510 and second contact
holes 560 and 580 formed to penetrate the protection layer 622 so
as to expose a part of the connection wiring 550.
That is, in the second embodiment, the signal pad 510 and the test
wiring portions 520 and 520' are formed of the gate metal layer,
and a connection wiring 550 of the source/drain metal layer which
is the connection wiring between the signal pad 510 and the test
wiring portions 520 and 520' is formed on another layer. The signal
pad 510 and the test wiring portions 520 and 520' are connected to
the connection wiring 550 by means of the jumping wirings 530 and
530' formed of a material of the pixel electrode.
FIG. 6 is a sectional view illustrating an area near the test
wirings according to the second embodiment, in which a cross
section of the thin film transistor is shown on a right side.
As shown on a left side of FIG. 6, according to the second
embodiment, the display panel includes test wiring portions 520 and
520' and the signal pad 510, which are formed of a material
identical to that of a gate electrode 612 of a thin film transistor
in a process identical to that of forming the gate electrode 612, a
connection wiring 550 formed of a material identical to that of a
source/drain electrode 620 on a layer identical to that of the
source/drain electrode 620, in which a gate insulation layer 614 is
interposed between the connection wiring 550 and the test wiring
portions 520 and 520' or the signal pad 510. The display panel
further includes a jumping wiring 530 formed of a material
different from that of the test wiring portions 520 and 520' and
the connection wiring 550 and formed on a layer different from that
of the test wiring portions 520 and 520' and the connection wiring
550, for electrically connecting the connection wiring 550 and the
signal pad 510 with the test wiring portions 520 and 520'.
According to the second embodiment, in the case where static
electricity is generated in a process of testing the panel, such as
an array test and the like, when an electric charge of static
electricity reaches the jumping wiring 530 consisting of a
heterogeneous material (in other words, a material that is
different from a material of the test wiring portions 520 and 520'
and/or of the signal pad 510) while it is electrified through the
test wiring portions 520 and 520', a movement of the electric
charge is disturbed due to a difference of electric conductivity,
and a connection of two materials is broken due to a difference of
mobility of the electric charge, so as to cause a phenomenon in
which two materials are electrically short-circuited. Accordingly,
it is possible to prevent an inflow of the static electricity into
the panel through the test wiring portions.
FIG. 7 is a view illustrating a process of fabricating an array
substrate having a configuration capable of preventing static
electricity according to the second embodiment of the present
invention.
Firstly, a gate metal material consisting of a metal material with
low electrical resistance including at least one of aluminum (Al),
aluminum alloy such as aluminum neodym alloy (AlNd), copper (Cu),
copper alloy, molybdenum (Mo), and molybdenum alloy such as
molybdenum titanium alloy (MoTi), is deposited and patterned on a
surface of a transparent insulation substrate 610 formed of a glass
or plastic material, thereby forming the test wiring portions 520
and 520' and the signal pad 510.
In the process, a gate line (not shown) connected to each pixel
area and a gate electrode 612 of a driving TFT or a pixel TFT may
be simultaneously formed together.
A gate insulation layer 614 consisting of an insulation substance
is formed on the substrate 610 on which the gate electrode 512, the
test wiring portions 520 and 520', and the signal pad 510 are
formed (see step A of FIG. 7).
Next, in the process of forming a source/drain electrode 620 on a
semiconductor layer 616 and an ohmic contact layer 618 after
forming the semiconductor layer 616 and the ohmic contact layer 618
on the gate insulation layer 614 in the form of an island, a
connection wiring 550 made of a source/drain metal material is
formed between the inspection pad 520' and the signal pad 510 in a
thin film transistor area (See step B of FIG. 7).
In this event, the connection wiring 550 may be formed so that both
ends thereof partially overlap ends of the inspection pad 520' and
the signal pad 510, respectively.
The process of forming the semiconductor layer 616 and the ohmic
contact layer 618, and the use of the etch stopper instead of the
formation of the semiconductor layer 616, correspond to the
description related to the first embodiment, and thus the detailed
description of the process and the use of the etch stopper will be
omitted to avoid a duplicate description.
Next, a protection layer 622 is formed on a surface of the
substrate on which a source/drain electrode 620 of a thin film
transistor area and a connection wiring of a test wiring area, and
a contact hole 624 is formed to penetrate the protection layer 622
so as to expose a part of the drain electrode of the thin film
transistor area in order to connect the pixel electrode. In the
process, the gate insulation layer 614 and the protection layer
622, which are arranged on ends of the inspection pad 520' and the
signal pad 510, are partially etched to form first contact holes
570 and 590 through which a part of the inspection pad 520' and the
signal pad 510 is exposed. Furthermore, a part of the protection
layer 522 located on both ends of the connection wiring 550 is
partially etched to form second contact holes 560 and 580 through
which a part of both ends of the connection wiring 550 is exposed
(see step C of FIG. 7).
Then, in the process of forming the pixel electrode 626 connected
to the drain electrode in the thin film transistor area, a jumping
wiring 530 and a jumping wiring 530' are formed in the test wiring
area, which electrically connect ends of the inspection pad 520'
and the signal pad 510, respectively, to both ends of the
connection wiring 550. Such jumping wirings 530, 530' may be formed
of a material identical to that of the pixel electrode, i.e., a
transparent conductive material having a relatively large work
function value, for example, a metal oxide such as Indium-Tin-Oxide
(ITO) or Indium-Zinc-Oxide (IZO), a combination of a metal and an
oxide, such as ZnO:Al or SnO2:Sb, and the like (see step D of FIG.
7).
Further, in the second embodiment shown in FIGS. 5, 6, and 7, it is
described as an example that the test wiring portions 520 and 520'
and the signal pad 510 are formed of a gate metal layer, and the
connection wiring 550 is formed of a source/drain metal layer, but
the second embodiment is not limited thereto. In the second
embodiment, the test wiring portions and the signal pad may be
formed of the source/drain metal layer, and the connection wiring
may be formed of the gate metal layer.
FIGS. 8A and 8B are views illustrating modifications of the first
and second embodiments of the present invention.
FIG. 8A shows a modification of the first embodiment. In the first
embodiment shown in FIGS. 2, 3 and 4, it is described that the test
wiring portions 220 and 220' and the signal pad 210 are formed on
an identical layer (a gate layer or a source/drain layer). However,
as shown in FIG. 8A, the test wiring portions 220 and 220' and the
signal pad 210 may be formed on different layers, respectively.
For example, as shown in FIG. 8A, the test wiring portions 220 and
220' are formed of a material identical to that of the gate metal
layer on a layer identical to that of the gate metal layer, and the
signal pad 210 is formed of a material identical to that of the
source/drain metal layer on a layer identical to that of the
source/drain metal. The jumping wiring 230 interposed between the
test wiring portions 220 and 220' and the signal pad 210 may be
formed of a material identical to that of the pixel electrode on a
layer identical to that of the pixel electrode. In another example,
the test wiring portions 220 and 220' may be formed of the
source/drain metal layer, and the signal pad 210 may be formed of
the gate metal layer.
FIG. 8B shows a modification of the second embodiment. Although it
is described that the jumping wirings 530 and 530' are formed at
both ends of the connection wiring 550 in the embodiment shown in
FIGS. 5, 6 and 7, the embodiment is not limited thereto. As shown
in FIG. 8B, the jumping wiring may be formed only at one end of the
connection wiring 550.
For example, as shown in FIG. 8B, both the test wiring portions 520
and 520' and the signal pad 510 may be formed of the gate metal
layer, and the connection wiring 550 may be formed of the
source/drain metal layer. One side or end of the connection wiring
550 may be directly connected to the signal pad 510 through a
contact hole which penetrates a gate insulation film 914 and, at
the other side-part or end of the connection wiring 550, the
jumping wiring 530 made of a material of the pixel electrode may be
formed through a first contact hole formed to penetrate the gate
insulation film 914 and the protection layer 922 arranged on the
inspection pad 520' and a second contact hole formed to penetrate
the gate insulation film 914 arranged on the other side or end of
the connection wiring 550. In another example, the inspection pad
520' may be directly connected to a side or end of the connection
wiring 550, and the signal pad 510 and the other side or end of the
connection wiring 550 may be connected by means of the jumping
wiring 530.
As described above, according to the embodiments of the present
invention, while static electricity generated in an array test
process of the display panel of the liquid crystal display device
or the organic light emitting display device flows into the panel,
a discharge of the static electricity is induced at a connection of
the jumping wiring formed of a material different from that of the
test wiring or the signal pad. Accordingly, there is an advantage
in that the panel is prevented from being damaged due to the inflow
of the static electricity generated in the array test process into
the panel.
It will be apparent to those skilled in the art that various
modifications and variations can be made in the display panel of
the present invention without departing from the spirit or scope of
the invention. Thus, it is intended that the present invention
cover the modifications and variations of this invention provided
they come within the scope of the appended claims and their
equivalents.
* * * * *